I/EC
Reports
THE EDITORS ANALYZE A N D INTERPRET THE CHEMICAL WORLD THIS M O N T H
Chemical Capsules Never Forget W o r k on carbonless carbon p a p e r points to possible chemical memory for computers VrfOMPUTERS seem well on their way to becoming an integral part of the chemical world. And it appears now that certain chemicals could become integral parts of computers. Specifically, National Cash Register's work with its carbonless carbon paper, now a multimillion dollar business, contains the germ of an idea for a chemical memory device. In fact, it's no longer just a germ ; N C R is working on it in a preliminary way. C o m p u t e r memory devices are basically switching devices. These can be electromechanical, like relays, or electronic, like vacuum tubes, transistors, and magnetic cores. N C R bases its chemical a p p r o a c h on the very closely controlled emulsification process worked out for use on its duplicating paper. T h e idea, there, was to make a colorless, oil-soluble dye react with a claylike material to give a bluish green color. N C R had to put these two phases on paper so that they would get together and react only when the user wanted them to—namely, when he was making " c a r b o n " copies. Doing this took some evolution, and N C R will not be specific on either the compounds or the process it uses. But the principle is to coat drops of the oil containing the dye with a gelatinlike material. The.se droplets a m o u n t to tiny, discrete capsules with high stability. Their size can be controlled closely; those used on N C R ' s duplicating paper are in the 2- to 3-micron range. Each sheet of duplicating paper
bears a film of capsules on one side, a film of the claylike material on the other. I n use, the paper is stacked so that a claylike surface is always next to a capsule surface. Pressure from pencil, pen, typewriter key, and the like breaks the capsules at the point of impact, releasing the dye. It reacts with the claylike coating on the adjacent sheet to give a " c a r b o n " copy. T h e chemical memory device would use the capsules, but without breaking them. Instead, they would contain a photosensitive dye which changes color when exposed to light of a certain wave length. (Capsule walls would be transparent to the light.) T h e dye returns to its original color when exposed to another wave length, remains unchanged in either color state when exposed to " n e u t r a l " wave lengths. N C R finds it can encapsulate such dyes and put a film of capsules on paper and other surfaces. This memory surface would act something like magnetic tapes and cores, which store information as magnetized spots. Light of the proper wave length would hit the coated surface, producing a colored spot. Light of another wave length would " e r a s e " the information by returning the spot to its original color. Light of a neutral wave length would " r e a d " the information stored on the surface. W h e t h e r reflected by the surface or transmitted through it, the neutral beam's characteristics would respond to the color pattern— the stored information—on the surface. These effects, boosted by photomultiplier circuits, would be translated to electronic signals for use by other circuits in the computer. As the capsules can be m a d e very small, millions of them could be put on a square inch of surface. Size of the memory spots, however, is limited by optical resolution rather than capsule size. Despite this situation, N C R believes high capacity might be one advantage of such a memory device. Another advantage might be relatively low cost. How-
ever, both of these presumptions— especially the one on cost—depend on the outcome of problems yet unsolved. These problems are m a n y and complex. I n general, they concern development of suitable input-output systems to complement the chemical memory surface. While NCR thinks they can probably be solved, it believes the first practical chemical memory or switching device of this kind is still some time in the future. K.M.R.
Isomerization: Key to High Octane Fuels of Tomorrow Refiners may face problems in making t o morrow's premium gasolines; new processes may be needed to match high octane—high compression ratio trends ISOMERIZATION processes to make high octane motor fuel components may be in wide use in the next few years. This prediction is m a d e freely by m a n y in the petroleum industry. Reason for their outlook: Some refiners m a y have severe problems in making p r e m i u m grade gasolines in the 100 or above octane range, should the present octane and auto compression ratio trends continue : • Premium gasoline octanes averaged 98.2 in June (F-1 Research method); expected to reach 103 by 1961 and average 105 by 1966. One source predicts octanes may near 110 by 1960. • Auto engine compression ratios average 9 to 1 now; expected to average 11 to 1 by 1961 T o d a y some 6 % of cars in use have compression ratios around or VOL 49, NO. 8
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AUGUST 1957
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